each file for the downloader ends in a signature
signatures can be found by the hex string
01000000 00000000 00000000 00000000
followed by high-entropy bytes (basically no zeroes, no readable text or repeated values nearby)

0x0 ... 0x2000 -> whatever, BL1
0x2000 ... 0x15000 -> second image (encrypted TZ/EL3?)
0x15000 ... 0x64000 -> ACPM and other stuff
0x7D000 ... 1FD000 -> BL2, the actual s-boot

There are actually multiple images starting from 0x15000
but there is only one signature at the end.

0x15000 ... 0x30c00 -> XXX
0x30C00 ... 0x7d000 -> YYY
	One of XXX and YYY is unknown and one is:
	ACPM (Power controller) firmware, unsigned?



dd if=sboot.bin of=part1.bin bs=$((0x2000)) count=1
dd if=sboot.bin of=part2.bin bs=1 skip=$((0x2000)) count=$((0x15000-0x2000))
dd if=sboot.bin of=part3.bin bs=1 skip=$((0x15000)) count=$((0x64000-0x15000))
dd if=sboot.bin of=part4.bin bs=1 skip=$((0x7d000)) count=$((0x1fd000-0x7d000))